plugging a hole

[Andy330hp]

I have what I thought would be a basic problem, but have as yet found no information.

All I want to do is plug a hole

On one of our parts, we must make multiple bores to acheive the internal geometry that we want. Some of these bores must then be plugged to prevent air leaks, fuel leaks, etc (it's a TBI throttle body, and the passages are fuel passages and IAC passages).

I was envisioning using something that looked like a miniature freeze plug, and whether it be made of steel, brass, or aluminum I don't care, I want the easiest and cheapest solution. I was also thinking of lead (or something similar but less toxic) that would be easy to press in and maintain a good seal.

this seems like a common issue, so surely I'm typing the wrong words into google!

 

[Retracnic]

Andy,

Since this is a throttle body, I will have to assume that the holes in question are of a relatively small diameter. What I'd do is this. Tap the holes for the nearest appropriate thread/bolt size. Use a hacksaw to saw off the end of a bolt or stud to the correct length. Slot the end for a screwdriver. Dab on some Loctite (or the thread sealer of your choice). Screw it in the hole and call it a day. It's a cheap solution, and is removable if need be.

Or you could just use a silicon rubber plug for the holes that won't come into contact with fuel.

Good Luck
Bryan Carter

 

[PJGD]

It is evident that what you need is an expander plug. Try:-

http://www.theleeco.com/LEEweb2.nsf/AeroStart!OpenPage

or

http://www.sherexusa.com/Products/Koenig/koenig_sealing_plugs.html

PJGD

 

[Andy330hp]

Both of those are really slick, but are probably overkill (too expensive) for what we need. We'd probably also have to modify our design, as they require a lot of material. I need something like those, but shorter and simpler. The same thing goes for tapping the holes, it's a good idea for a one-off but seems overly complicated for a (admittedly small) production run.

 

[Pancholin]

Andy330hp
Why not drill the hole slightly undersize and drive a steel ball into it then peen the hole to make sure the ball can't escape?
Pancholin.

 

[JayMaechtlen]

The others are pricey.
Assuming a low pressure differential across the thing, you can use simple cup-type plugs.
As used in auto engine blocks, called "freeze p;ugs" or "core plugs" to us user types.

Also used in carburetors and similar devices to plug holes in low-pressure applications.

One name in that line of stuff is Dorman - don't know if they make or just market the things...


Jay Maechtlen

 

[sprintcar]

How about short self-tapping screws? I think you can get thread forming set screws (headless) if the external appearance is an issue. Use stud grade loctite as a lube/sealant.

Keep the wheels on the ground
Bob
showshine@aol.com

 

[JayMaechtlen]

core plugs: one example

http://www.mercprod.com/products_we_sell/core_plugs.html

Of course, it depends on a lot of things, which way to go.
cheers

Jay Maechtlen